The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1999
Filed:
Oct. 10, 1997
Kabushiki Kaisha Toyota Chuo Kenkyusho, Aichi-ken, JP;
Abstract
A compact voltage sensor with stable characteristics is provided. A measuring beam that is incident from an optical fiber is branched into first and second modulation-inducing waveguides of a wave branching/combining section within an optical integrated circuit. Phase changes of opposite sign are induced in the measuring beams propagating within the first and second modulation waveguides by applying voltages of mutually opposite sign to modulation-inducing electrodes, to induce a phase difference between the two. By reflecting the measuring beams from a reflective surface, propagating them back in the opposite direction within the first and second modulation waveguides, and passing them through the optical intensity modulation section again, thus applying a further phase modulation thereto, the phase difference between the measuring beams proceeding in the opposite direction within the first and second modulation waveguides can be made to be substantially twice the phase difference of the measuring beams before they are reflected by the reflective surface. The sensor also has a function to protect a sensor section thereof from dielectric breakdown caused by the accidental input of a high voltage.